Stands for "I Hate It When", is a type of post that you would put up on ihateitwhen.com . This site lets you post up all your pet peeves or annoyances and lets peoplerate/agree with them.
IHIW you lay down on the couch and get nice and comfortable only to realize the remote is nowhere in reach.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.